The need is currently felt, in the most disparate sectors and fields of application, to be able to locate and identify precisely a portable container (such as suitcases, trunks and the like) and its contents, particularly when it passes through certain environments, or during its controlled and monitored transit from one environment to another, for example due to storage logistics reasons or also and especially due to security reasons. Consider, merely by way of example, the transit of suitcases and trunks in airports or upon entering certain environments or buildings which are critical in terms of security.
Problems of this type are usually solved for example by resorting to metal detectors, which require the preparation of suitable facilities with high costs and considerable space occupation; in other cases it is instead necessary to open in each instance the container in order to examine its contents carefully.